import pandas as pd
data = {
    'Name': ['Alice', 'Bob', 'Charlie'],
    'Age': [25, 30, 35],
    'Score': [88.5, 92.0, 78.5]
}
df = pd.DataFrame(data)
print(df['Name'])  # 选择单列
print('-'*35)
print(df[['Name', 'Score']])  # 选择多列
